code: def test_backward_non_default_gpu(self):
      x0 = chainer.Variable(cuda.to_gpu(self.x0, 1))
      x1 = chainer.Variable(cuda.to_gpu(self.x1, 1))
      gy = cuda.to_gpu(self.gy, 1)
      with cuda.get_device_from_id(0):
          y = functions.absolute_error(x0, x1)
          y.grad = gy
          y.backward()
  
file_path: chainer/tests/chainer_tests/functions_tests/loss_tests/test_absolute_error.py
imports: import unittest
  import numpy
  import chainer
  from chainer.backends import cuda
  from chainer import functions
  from chainer import testing
  from chainer.testing import attr
  from chainer import utils
label_desc: Use image node_id 2 for calling the TestNonDefaultGPU obj's underlying member method code with example usage: obj.test_backward_non_default_gpu() without return types